Michelle had the secret love child with Domenici in 1978. She called it a "one night's mistake."

Their 34-year-old son, Adam, is now a successful Las Vegas lawyer.

"I raised my son as a single parent surrounded by love and joy and opportunity," she said.

Domenici, who retired from the Senate in 2008, said in a statement, "I am very sorry for my behavior."

Judy Kurtz of The Hill weighed in, saying, "Thirty years ago, if this had gotten out while he was a lawmaker it really could have meant the end for him. Instead, he was New Mexico's longest-serving Senator."

Michelle Laxalt and Peter Domenici went public with their closely guarded secret this week because they were concerned that it was about to be exposed in the media.